I only use 100% flat curves on mine, haven't used V-curves since non-gov days, lol. Anyway, did you recalibrate your 7100r again after you rebuilt your motor?

Gaui Greatness X7, X5, NX4, X3

The thing Im wondering that wasnt mentioned in the OP.Was it working before? And then all that has changed is motor work(bearings)?

How exactly are you controlling the gain(atv)for the Gear chan?
You say its off in Normal.So you have Chan5 set to center and then use one mix to set the rpm in Idl1&2 to 2050? Or two different headspeeds for Idl 1&2? 2 mixes? Did you set it up? Did you confirm that nothing was changed in the radio to change Chan5 values? You didnt say anything about Idl1.Is the rpm correct there? Or do you just jump from Normal to 2?

If its gaining rpm going from Idl2 to normal it sounds like the values for Chan5 arent right. If it was right before and it is actually working(it must be if its not going WOT in Idl with 100% flat TCurve) changing the sensor distance shouldnt change the value.Unless the sensor was farther away before and it is now seeing the crankpin also and seeing 2 blank spots instead of 1.

What is Chan5 doing on the Monitor screen when you change FModes?
Calibrating the Rx could help but if it was correct before and you didnt change any electronic components it shouldnt have changed.

Ok, changing the rate to -100% in prog mix 1, has not disabled the limiter in normal mode.

It sounds like maybe it didnt get calibrated correctly.
I think maybe you are making it far more complicated than necessary.
First Inhibit all the mixes.When you calibrate the channel has to move 100/100 when you enter calibration.Then move the throttle stick up and down.Exit calibration.
Then go and set the mixes and values in one of the ways I suggested in the other thread.Personally I would set a limiter for all 3 modes.Its much simpler and you only use 2 mixes.You dont have to worry about getting the center/off position right and it just works.If you want it to be off just flip the Gear switch down.Its effectively off with a 100% value.
If your going to try and get 2050 headspeed with 8.6:1 gearing your going to need 17630 engine rpm.Look at the table in the manual.Your basically at 100% gain to get there.Actually 100% gives 17340.Divide by 8.6 and you have 2016.An 8.5 gear will get you 2050.

I never had good luck setting it with the math and the graph numbers.I just use it to give a rough idea where I should be and what is possible.
I always seem to be a little faster than what the math gives me so I fine tune with a tach accordingly.

So in Idl2 your basically going to be looking for close to 100 on the channel.If you want 1900 in Idl1 maybe around 90.
What rpm are you looking to have in Normal? Alot,or just enough to take off and land?

Your also leaving out the info about switch assignment for each mix.This matter alot.Simlpy putting the mixes in doesnt work without unique switch assignments for each.